Volume infusion is the initial management of shock due to sepsis. Because of recent evidence generated in our unit, that there is depressed myocardial performance in human septic shock, we have analyzed left ventricular performance during volume infusion using serial hemodynamic data obtained from pulmonary artery catheters and radionuclide cineangiography. Responses to fluid were assessed in critically - ill, nonseptic "controls" and in patients with sepsis and septic shock. All groups received statistically similar amounts of volume infusion and all increased their pulmonary capillary wedge pressure by statistically similar amounts. Left ventricular stroke work, a measurement of ventricular performance, was not responsive to volume infusion in septic patients, indicating abnormal ventricular contractility due to sepsis. There is also preliminary evidence of a trend toward abnormal ventricular compliance as manifested by decreased ability of the ventricle to dilate in response to volume infusion in septic patients. Further clinical studies are underway to better clarify the pathogenesis of these alterations in left ventricular performance in septic patients.